PSF model

docs/changes/2643.feature.rst

@@ -1,4 +1,2 @@
-Adds psf models to ``ctapipe.instrument.optics`` with the parent class ``PSFModel`` and a psf model based on pure coma abbaration called ``ComaModel``
-- All psf models have a function ``PSFModel.update_location`` that updates the location in the focal plane where the PSF is evaluated from
-- The function ``PSFModel.update_model_parameters`` allows to update the parameters of the PSF model
+Adds psf models to ``ctapipe.instrument.optics`` with the parent class ``PSFModel`` and a psf model based on pure coma aberration called ``ComaModel``
 - The function ``PSFModel.pdf`` gives the value of the PSF in a given location

src/ctapipe/instrument/optics.py

@@ -312,7 +312,7 @@ class ComaModel(PSFModel):
     radial_scale_params describes the dependency of the radial scale on the distance to the center of the camera
     Used to calculate width Sr of the asymmetric radial laplacian in the PSF as a of function the distance r to the optical axis
 
-    .. math:: S_{R}(r) & = b_1 - b_2\,r + b_3\,r^2 + b_4\,r^3
+    .. math:: S_{R}(r) & = b_1 + b_2\,r + b_3\,r^2 + b_4\,r^3
 
     az_scale_params Describes the dependency of the azimuthal scale on the distance to the center of the camera
     Used to calculate the width Sf of the azimuthal laplacian in the PSF as a function of the angle :math:`phi`

src/ctapipe/instrument/tests/test_psf_model.py

@@ -7,26 +7,43 @@
 from ctapipe.instrument.optics import PSFModel
 
 
-def test_psf(example_subarray):
+@pytest.fixture(scope="session")
+def asymmetry_params():
+    return [0.49244797, 9.23573115, 0.15216096]
+
+
+@pytest.fixture(scope="session")
+def radial_scale_params():
+    return [0.01409259, -0.02947208, 0.06000271, -0.02969355]
+
+
+@pytest.fixture(scope="session")
+def az_scale_params():
+    return [0.24271557, 7.5511501, 0.02037972]
+
+
+def test_psf(example_subarray, asymmetry_params, radial_scale_params):
     with pytest.raises(
         ValueError,
         match="asymmetry_params and az_scale_params needs to have length 3 and radial_scale_params length 4",
     ):
         PSFModel.from_name(
             "ComaModel",
             subarray=example_subarray,
-            asymmetry_params=[0.49244797, 9.23573115, 0.15216096],
-            radial_scale_params=[0.01409259, 0.02947208, 0.06000271, -0.02969355],
-            az_scale_params=[0.24271557, 7.5511501],
+            asymmetry_params=asymmetry_params,
+            radial_scale_params=radial_scale_params,
+            az_scale_params=[0.0],
         )
 
 
-def test_asymptotic_behavior(example_subarray):
+def test_asymptotic_behavior(
+    example_subarray, asymmetry_params, radial_scale_params, az_scale_params
+):
     psf_coma = PSFModel.from_name(
         "ComaModel",
         subarray=example_subarray,
-        asymmetry_params=[0.49244797, 9.23573115, 0.15216096],
-        radial_scale_params=[0.01409259, 0.02947208, 0.06000271, -0.02969355],
-        az_scale_params=[0.24271557, 7.5511501, 0.02037972],
+        asymmetry_params=asymmetry_params,
+        radial_scale_params=radial_scale_params,
+        az_scale_params=az_scale_params,
     )
     assert np.isclose(psf_coma.pdf(10.0, 0.0, 1.0, 0.0), 0.0)